A possibly encouraging study from UKIC/PHE that relates to Mike Yeadon’s T-cell mediated immunity claim.
Cellular immunity to SARS-CoV-2 found at six months in non-hospitalised individuals:
https://www.uk-cic.org/news/cellular-immunity-sars-cov-2-found-six-months-non-hospitalised-individuals
(Please note, this paper is a pre-print reporting preliminary data that has not yet been peer-reviewed.)
This has hit the media today. Whilst it is encouraging it should be noted that it is NOT definitive evidence of T-cell mediated immunity. Prof Moss, one of the authors has said:
“I think this data is reassuring, potentially even encouraging, but it does not mean that people cannot get re-infected.”
He added that large-scale population studies are needed to show how the antibody and cellular profiles can act together and protect people over time.
“This cannot be taken as confirmation of an immunity passport. Absolutely cannot do that”
Prof Eleanor Riley, Professor of Immunology and Infectious Disease, University of Edinburgh said immunity is a functional term that implies resistance to infection, and this she says, has not been directly shown in this study.
“Determining whether these T cell responses are protective against reinfection would require either an experimental infection study (such studies are under active discussion) or a very large, long term study to assess the frequency of reinfection in people whose T cell responses have been measured.
“Given the apparently very low incidence of reinfections at the current time, such a study would not currently be a high priority.”
Cautious optimism is in order. I think Mike Yeadon is being overly optimistic in claiming studies demonstrating T-cell reactivity to Sars-Cov-2 is evidence of immunity. It might be but then again it might not and has yet to be proven. The 30% cross immunity from other corona viruses is even more optimistic.